Avoiding Alzheimer’s Disease Could Be Easier Than You Think

Science shines bright light on root cause of memory problems.

If you don’t know, you’re not alone. This is perhaps the single most important question any of us can ask about our physical and mental health—yet most patients, and even many doctors, don’t know how to answer it.

Here in the U.S., insulin resistance has reached epidemic proportions: more than half of us are now insulin resistant. Insulin resistance is a hormonal condition that sets the stage throughout the body for inflammation and overgrowth, disrupts normal cholesterol and fat metabolism, and gradually destroys our ability to process carbohydrates.

Scarier still, researchers now understand that insulin resistance is the driving force behind most cases of garden-variety Alzheimer’s Disease.

What is insulin resistance?

Insulin is a powerful metabolic hormone that orchestrates how cells access and process vital nutrients, including sugar (glucose).

In the body, one of insulin’s responsibilities is to unlock muscle and fat cells so they can absorb glucose from the bloodstream. When you eat something sweet or starchy that causes your blood sugar to spike, the pancreas releases insulin to usher the excess glucose out of the bloodstream and into cells. If blood sugar and insulin spike too high too often, cells will try to protect themselves from overexposure to insulin’s powerful effects by toning down their response to insulin—they become “insulin resistant.” In an effort to overcome this resistance, the pancreas releases even more insulin into the blood to try to keep glucose moving into cells. The more insulin levels rise, the more insulin resistant cells become. Over time, this vicious cycle can lead to persistently elevated blood glucose levels, or type 2 diabetes.

Insulin resistance and the brain

In the brain, it’s a different story. The brain is an energy hog that demands a constant supply of glucose. Glucose can freely leave the bloodstream, waltz across the blood-brain barrier, and even enter most brain cells—no insulin required. In fact, the level of glucose in the cerebrospinal fluid surrounding your brain is always about 60% as high as the level of glucose in your bloodstream—even if you have insulin resistance—so, the higher your blood sugar, the higher your brain sugar.

Not so with insulin—the higher your blood insulin levels, the more difficult it can become for insulin to penetrate the brain. This is because the receptors responsible for escorting insulin across the blood-brain barrier can become resistant to insulin, restricting the amount of insulin allowed into the brain. While most brain cells don’t require insulin in order to absorb glucose, they do require insulin in order to process glucose. Cells must have access to adequate insulin or they can’t transform glucose into the vital cellular components and energy they need to thrive.

Despite swimming in a sea of glucose, brain cells in people with insulin resistance literally begin starving to death.

Insulin resistance and memory

Source: Suzi Smith, used with permission

Which brain cells go first? The hippocampus is the brain's memory center. Hippocampal cells require so much energy to do their important work that they often need extra boosts of glucose. While insulin is not required to let a normal amount of glucose into the hippocampus, these special glucose surges do require insulin, making the hippocampus particularly sensitive to insulin deficits. This explains why declining memory is one of the earliest signs of Alzheimer’s, despite the fact that Alzheimer’s Disease eventually destroys the whole brain.

This does not mean that diabetes causes Alzheimer’s Disease—dementia can strike even if you don’t have diabetes. It’s more accurate to think of it this way: Insulin resistance of the body is type 2 diabetes; insulin resistance of the brain is type 3 diabetes. They are two separate diseases caused by the same underlying problem: insulin resistance.

Are you already on the road to Alzheimer’s Disease?

You may be surprised to learn that Alzheimer’s Disease begins long before any symptoms appear.

The brain sugar processing problem caused by insulin resistance is called “glucose hypometabolism.” This simply means that brain cells don’t have enough insulin to burn glucose at full capacity. The more insulin resistant you become, the more sluggish your brain glucose metabolism becomes. Glucose hypometabolism is an early marker of Alzheimer’s disease risk that can be visualized with special brain imaging studies called PET scans. Using this technology to study people of different ages, researchers have discovered that Alzheimer’s Disease is preceded by DECADES of gradually worsening glucose hypometabolism.

Brain glucose metabolism can be reduced by as much as 25% long before any memory problems become obvious. As a psychiatrist who specializes in the treatment of college students, I find it positively chilling that scientists have found evidence of glucose hypometabolism in the brains of women as young as 24 years old.

Real hope for your future

We used to feel helpless in the face of Alzheimer’s Disease because we were told that all of the major risk factors for this devastating condition were beyond our control: age, genetics, and family history. We were sitting ducks, living in fear of the worst—until now.

The bad news is that insulin resistance has become so common that chances are you already have it to some degree.

The good news is that insulin resistance is a major risk factor for Alzheimer’s Disease that you CAN do something about.

Eating too many of the wrong carbohydrates too often is what causes blood sugar and insulin levels to rise, placing us at high risk for insulin resistance and Alzheimer’s Disease. Our bodies have evolved to handle whole food sources of carbohydrates like apples and sweet potatoes, but they simply aren’t equipped to cope with modern refined carbohydrates like flour and sugar. Simply put, refined carbohydrates cause brain damage.

You can’t do anything about your genes or how old you are—but you can certainly change how you eat. It's not about eating less fat, less meat, more fiber, or more fruits and vegetables. Changing the amount and type of carbohydrate you eat is where the money's at.

3 steps you can take right now to minimize your risk for Alzheimer’s Disease:

1. Find out how insulin resistant you are.

Your health care provider can estimate where you are on the insulin resistance spectrum using simple blood tests such as glucose, insulin, triglyceride, and HDL cholesterol levels, in combination with other information such as waist measurement and blood pressure. In this article, I include a downloadable PDF of tests with healthy target ranges for you to discuss with your health care provider, and a simple formula you can use to calculate your own insulin resistance.

2. Avoid refined carbohydrates like the plague, starting right now.

Even if you don’t have insulin resistance yet, you remain at high risk for developing it until you kick refined carbohydrates such as bagels, juice boxes and granola bars to the curb. For clear definitions and a list of refined foods to avoid, click here.

3. If you have insulin resistance, watch your carbohydrate intake.

Unfortunately, people with insulin resistance need to be careful with all carbs, not just the refined ones. Replace most of the carbs on your plate with delicious healthy fats and proteins to protect your insulin signaling system. The infographic below provides key strategies you'll need to normalize blood sugar and insulin levels.

You can wield tremendous power over insulin resistance—and your intellectual future—simply by changing the way you eat. Laboratory tests for insulin resistance respond surprisingly quickly to dietary changes—many people see dramatic improvements in their blood sugar, insulin, and triglyceride levels within just a few weeks.

If you already have some memory problems and think it’s too late to do anything about it, think again! This 2012 study showed that a low-carbohydrate high-fat diet improved memory in people with “Mild Cognitive Impairment” (Pre-Alzheimer’s Disease) in only six weeks.

Yes, it is difficult to remove refined carbohydrates from the diet—they are addictive, inexpensive, convenient, and delicious—but you can do it. It is primarily your diet, not your DNA, that controls your destiny. You don’t have to be a sitting duck waiting around to see if Alzheimer’s Disease happens to you. Armed with this information, you can be a proactive, swimming duck sporting a big, beautiful hippocampus who gets to keep every single one of your marbles for the rest of your life.

Great summary of the insulin link to Alzheimer's - raised insulin looks increasingly like a risk factor for diabetes (obviously but the charities are having a hard time performing the necessary u-turn on dietary advice) as well as cancer.

Thought you might be interested in why lowering homocysteine with B vitamins is also a very promising preventitive approach. Readers may have picked up on some studies claiming to have disproved the link but they are examples of shockingly poor science.

Why very high B vitamins make sense - if your homocysteine is high - and why the studies claiming to disprove this do nothing of the sort can be seen here:

Interesting! Thanks for sharing. In addition, researchers recommend prioritizing sleep. "A single night of sleep deprivation can cause as much insulin resistance as six months on a high-fat diet" Cedar Sinai 2015 research: Sleep well to avoid insulin resistance.

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So true, Stephen! Of course the majority of studies I read conclude by considering which drugs might be used to improve insulin resistance! This is the same approach being taken with diabetes, too, sadly. There are even studies using insulin sprayed into the brain via the nostrils to try to overcome insulin resistance in the brain. Yes, insulin-sensitizing drugs and even insulin itself DO work to improve memory in these studies, but a) they are band-aids that don't address the root cause and b) they are expensive and have side effects. There's no money in selling people a healthy diet. Sigh.

My mother just passed away from Alzheimers (my father passed last year from diabetes and strokes) and I have the "Altzheimers gene". I started a low carbohydrate diet four years ago and at 58 have I never felt better. Low carb eating plus exercise is my plan to avoid Altzheimers, diabetes, stroke and all the other Metabolic Syndrome health troubles. I love the simple, concise info graphic, but wish there was a printable version to post on the refrigerator. Thank you so very much for this life-saving article.

First, Laura, I'm so sorry to hear about your parents' passing. It is tragic to lose so many of our loved ones to potentially preventable diseases.

As for a printable version of the infographic, I spoke with Suzi Smith, who created it. She said that because it is one continuous, long vertical image, it wouldn't be easy to create a printable version of it.

However, if you go to the original article on my site: http://www.diagnosisdiet.com/how-to-diagnose-prevent-and-treat-insulin-resistance/ , and scroll to the bottom of the infographic, you'll see the phrase "if you're unable to view this image, click here." Clicking on that link brings up a low-resolution JPEG that you can print. It won't print perfectly because of page breaks, but unfortunately that's the best we can do! Sorry for the inconvenience...

Hey! I had the same thought about the printable version so I went and just arranged the files. I took the title out but left all the available info. It wouldn't be considered "print ready" by industry standards but it's now 8.5 x 11 in a convenient pdf for anyone that wants to view/print. I'll leave the link up temporarily for the next few months.

Thanks for the great post and all your work. I believe Dr. Kraft found that close to 80% of the population has IR. If this is around the percentage for Alzheimers than the relative risk from IR would be very low. It suggests that the causal pathway is more complicated than just IR. It might be a necessary cause, but it probably isn't a sufficient one. It looks like there are other risk factors still to be discovered.
thanks, Jeff

I appreciate very much the concern that association should never be equated with causation. If it were simply that most people with AD have IR or T2D, I would be very skeptical indeed.

However, there are multiple lines of evidence all pointing in the same direction, including mechanistic, in vitro, animal, and even human clinical studies that all support the idea that Alzheimer's Disease is a metabolic disease with insulin resistance at its core. There isn't enough space in these brief PT articles to spell it all out, but if you are looking for more in-depth information, this article is a good place to start:

Great article! In addition to this I had short term memory loss which was caused from having a brain tumour and lack of oxygen getting to the brain. I regrew my brain after having it removed. My partner had memory loss and insulin resistance from being on statins for 20 years. He is now well again after stopping them. I had insulin dependent diabetes which I reversed with eáting low carb meals, reducing weight and exercising.

I'm sorry to hear about your father's situation. I certainly did not mean to imply that every case of all types of dementia is preventable. Eighty percent of people with Alzheimer's are insulin resistant or diabetes, but that leaves 20% of people who are not. There are other factors to be sure, but the science for prevention in most cases, particularly if one starts early, is very compelling. I believe people have nothing to lose by improving the quality of their diet but I hope I didn't come across as over-promising. Thank you for your feedback.

Why would you laugh, it means YOU will run the risk as well. Instead apply these tips. Your Dad could be IR and exercise and eat “well”. Most “healthy diets” are high in sugar and carbohydrates. Also most people who do fitness also consume higher carbohydrates than average. Good luck

I did not mean to imply that carbohydrates per se cause Alzheimer's Disease. The science strongly supports the notion that insulin resistance is a powerful player in Alzheimer's, not carbohydrate consumption itself. I don't know the rates of insulin resistance in Japan...but there have certainly been many cultures which have consumed high-carbohydrate diets and did not suffer from metabolic diseases. The primary difference between those dietary traditions and ours seems to be the presence of refined carbohydrates--flour, sugar, etc.

I, too, had the impression that you were against high-carbohydrate diets - from your promotion of low carb diets here and on your website, as well as statements from the info graphic: "root vegetables are just lumps of sugar wearing vegetable suits". Granted, the graphic follows by saying that people with insulin resistance, "may" need to limit sweet and starchy vegetables.

As a lay-person interested in nutrition, I like how your article got me thinking and how it sheds light on the damage caused by refined sugars, but I'm concerned that your solution is too limiting, and that it will discourage people.

Thank you for calling my attention to these questions, as I don't want to perplex anyone!

Many of our ancestors certainly included whole food sources of carbohydrates such as fruits and vegetables and there is evidence that isolated groups of modern-day people who ate this way did not suffer metabolic disorders. This suggests that if human beings stick to whole foods throughout their lifetime, they don't need to worry about how much carbohydrate they eat.

For people with damaged metabolism, I believe strongly in the power of low-carbohydrate diets in the treatment of metabolic disorders and recommend low-carbohydrate diets to people with insulin resistance.

People with healthy carbohydrate metabolism/insulin sensitivity are a different story--if they stick to whole food sources of carbohydrates they may be just fine for the rest of their lives--or it may depend on how much damage has already been done--I don't think anyone knows, but we should all certainly avoid refined carbs, regardless of our metabolic status.

As for grains and legumes, I disagree strongly with the WHO recommendations for reasons to complex to go into in this comment, but suffice it to say, these are relatively modern, post-agricultural foods, which our bodies handle very poorly indeed: http://www.diagnosisdiet.com/food/grains-beans-nuts-and-seeds/

I certainly don't want to discourage anyone, but my simple message is this:

If you are not insulin resistant yet, eat a whole foods diet including carbohydrates: meat/seafood/poultry/eggs +fruits
and vegetables.

What seems to be getting ignored here is a condition known as intramyocellular lipids, which is a leading cause of insulin resistance and one that is exacerbated by the consumption of a high fat diet (I've cited but a few studies in my post below that attests to this finding).

How then can advice to people suffering insulin resistance to consume a low carb diet and 'fat with every meal' possibly be reconciled with these findings?

Those intramyocellular lipids are put there (and not removed) by chronically elevated insulin + insulin resistance. Refined carbs are still the major driver of excess insulin, not naturally fatty foods.

There is no longer any such consensus. Numerous meta-analyses and experimental trials have either failed to find a connection between sat fat and disease, or have found _beneficial_ effects of eating more naturally fatty foods. "Nutrition facts" is a vegan advocacy website, and Greger is a poster-boy for sarcopenia and osteopenia.

Changing to the Western diet increases risk of Alzheimer's disease: In a paper just published electronically in the Journal of Alzheimer’s Disease, dramatic increases in Alzheimer’s disease (AD) in Japan and significant increases in developing countries are linked to changes in national diets.

The prevalence of AD for those aged 65+ years in Japan rose from 1% in 1985 to 7% in 2008. The prevalence of another major type of dementia, vascular dementia, was nearly constant at 4-5% during the same period.

Previous studies identified a number of risk factors for AD for which values in midlife or 15-30 years prior to diagnosis of AD are predictive: alcohol consumption, elevated cholesterol, diabetes mellitus, dietary fat, obesity, and smoking are associated with increased risk while physical fitness is associated with reduced risk.

YES--great video clip! Gary Taubes' phenomenal book Good Calories, Bad Calories was a major influence in my decision to study and write about nutrition and mental health. Unfortunately, despite that video being 4 years old and his book (which includes a few key pages about Alzheimer's and insulin resistance) being 9 years old now, most people have still not heard about the connection between insulin and Alzheimer's disease. Thank you for sharing this!

Diabetes can be minimized or reversed with a whole-food plant based diet. Eating animal products (meat, fish, diary) as well as oil is harmful. Eating a variety of plants (vegetables, fruits, nuts, seeds) gives you all of the protein and fat you need. There are not four food groups! There is just one... plants.

Check out http://www.forksoverknives.com/new-study-a-healthy-plant-based-diet-can-cut-type-2-diabetes-risk-by-a-third/

Unfortunately the study you referenced in the link you provide is an epidemiological study. Even the best epidemiological studies lack the power to demonstrate cause and effect--the best they can do is to generate a hypothesis that then must be tested in clinical trials.

Every clinical trial of plant-based diets that I am aware of claiming plant-based diets reverse diseases also removes refined carbohydrates, not just animal foods, so it's impossible to know whether the health benefits are due to the lack of animal foods, lack of refined carbs, or both.

And, Neal Barnard study, often touted by vegans, did NOT demonstrate any reversal of diabetes at all. Slight reductions in A1C after a year on the low-fat vegan diet, but the A1c was still in the diabetic range. Very dishonest research. This was no where near as powerful as the many studies which show diabetes reversal on a low carb diet.

Humans have been omnivores since before we were even human. Animal foods are nutrient dense and satiating to the appetite. A human with access to the modern supermarket, soy products, and supplements can get all essential nutrients on a vegan diet, but it is much _easier_ to be healthy, lean, and strong on a whole foods omnivorous diet.

To guard against all modern disease all we need to do is disregard "product" in favour of "real food". That means eating what should be available in the wild. Once this is done, it's possible to find the right balance of fat and protein by listening to your body as the body changes. As a hflc, I found this to be very interesting. Particularly regarding protein requirements. Carbs are in limited supply the further away from the equator you travel. As a consequence the need for carbs of those native to their environment is substantially decreased until not required at all. We all need to relearn what food actually is.

Bravo for getting this information out to the public, like me. :-) A brief research shows that this has been known for about ten years. How does resistant starch play a role in preventing insulin resistance? Evidence is pointing to the cooling of cooked pasta, or even better reheating it, lessens our insulin reaction.

One concern is that fruit juice and dried fruit both pack a wonderful potassium punch which is important for sugar metabolism which is why I keep those in my diet though now I will be more motivated to replace that with more veggies and vegetable juice.

1. Yes, resistant starches are much safer for our carbohydrate metabolism in most cases than other sources of carbohydrate because they don't tend to spike blood sugar. However, they can cause gastrointestinal distress for some people, particularly people with IBS.

2. Potassium is found in most foods and most people, to my knowledge, do not suffer potassium deficiency unless they are taking diuretic medications, so avoiding fruit should not cause any problem with potassium levels. People with insulin resistance need to be extremely careful with fruit due to its high sugar content. People without insulin resistance should be able to enjoy whole fruits. I hope you are one of them!

If you don't have insulin resistance, you can enjoy carrots without worrying about it.

If you have insulin resistance, you can eat carrots, you would just need to count their carbohydrate content towards you total daily maximum. Most people with insulin resistance need to keep their carbohydrates below 50 grams per day--and in most cases below 25 grams per day--but you could still have some carrot even if on a low-carbohydrate diet.

There are still plenty of non-cruciferous, low-carb plant foods out there to enjoy: jicama, spinach, chard, lettuce, celery, zucchini, cucumbers, spaghetti squash, eggplant, just to name a few.

The key connection between high glucose levels and type 2 diabetes and Alzheimer's disease is a toxic oxidant called peroxynitrite. Peroxynitrite mediates the nitration of the insulin receptor substrate causing insulin resistance and type 2 diabetes.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4191845/

http://www.ncbi.nlm.nih.gov/pubmed/15240096

Some of the glucose and insulin not able to enter cells in the rest of the body enter the brain and are converted into myo-inositol. High levels of myo-inositol increase the risk for Alzheimer's disease not so much because they increase amyloid beta but because they increase peroxynitrite (other factors that increase myo-inositol levels in the brain include high blood pressure due to high sodium levels and Down syndrome both of which are also risk factors for Alzheimer's disease).

Many other factors including environmental toxins and psychological stress can also increase peroxynitrite levels.

The damage done by a high sugar, high carbohydrate diet, and high sodium diet can be partially offset by plant polyphenols and fish oil. Ferulic acid in rice bran for instance is a very effective peroxynitrite scavenger (more on that later).

Peroxynitrite inhibits the synthesis and release of neurotransmitters involved in the retrieval of short-term memory, sleep, mood, social recognition and alertness; inhibits the flow of blood and the transport of glucose in the brain which may contribute to delusions, prevents the regeneration of neurons in the hippocampus, and contributes to the death of neurons.

Plant polyphenols called methoxyphenols are particular good peroxynitrite scavengers. This includes eugenol in various essential oils (including rosemary, clove, bay laurel, lemon balm, and cbd oil from marijuana) and ferulic acid and syringic acid in panax ginseng. These compound by scavenging peroxynitrite and by partially reversing nitro-oxidiative damage have led to the partial reversal of Alzheimer's disease in small-clinical trials.

http://www.ncbi.nlm.nih.gov/pubmed/20377818

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3659550/

http://www.ncbi.nlm.nih.gov/pubmed/22780999

In people with neuropsychiatric problems in Alzheimer's disease, myo-inositol levels remain high (in some cases due to high levels of psychological stress).

Lane, have you heard of and/or done any research on something called Protandim? Might be something to look into to help defeat peroxynitrite. Protandim is a Nrf2 regulator, while helps tell your own body to make its own antioxidants to combat free radicals/oxidative stress.

Just briefly, Nrf2 is regulated by the phosphatidyinositol 3-kinase/Akt pathway which is damaged by nitration (mediated by peroxynitrite) in Alzheimer's disease. Various peroxynitrite scavengers can partially reverse this nitration and thus increase the brain's own antioxidant systems.

Protandim consists of five ingredients: Milk thistle, Bacopa monniera, Aswagandha, green tee extract, and turmeric. All of these are good antioxidants. And combination therapy with various antioxidants may be a useful approach to treating Alzheimer's disease.

Potentially the best antioxidant in the group is turmeric high in curcumin. Curcumin is a very good hydrogen donor which is what is needed to first scavenge peroxynitrite and then to de-nitrate proteins. However, curcumin does not enter the bloodstream well, although researchers are working on ways to increase its absorption. Several other methoxyphenols such as ferulic acid, syringic acid, eugenol, sinapic acid, and vanillin have also showing effectiveness against Alzheimer's disease from in vitro studies to human clinical trials (in the cases of ferulic acid, syringic acid, and eugenol). While not dismissing the potential of Protandim, some combination of these antioxidants would likely provide the most effective treatment for the disease.

I apologize: one correction and an attempt to fix a broken leak. Glucose not insulin increases myo-inositol levels in the brain. And hopefully, this link to the abstract on ferulic acid and neuropsychiatric problems in Alzheimer's disease works.

I have been involved for several years in a crowd sourced study on the effects of Vitamin D and the levels necessary to achieve those effects. ( http://www.grassrootshealth.net/ ) One of many positive effects is a reduction in the likelihood of developing type 2 diabetes. Around 75% of Americans have very low levels of vitamin D, so that may be contributing to the diabetes. The advice to never let the sun shine on skin without sunblock is not helping! I have been living the ketogenic lifestyle for close to a year now (no sugar, low carbs, moderate protein and high fat), supplemented with 10,000 units of vitamin D3/day.. I am in my late 60's, have no memory problems and take no prescription drugs. One startling finding has been the extreme range of levels of D at the same level of consumption. Also, like many things, vitamin D levels decrease with age, so that is why I have found I now need 10,000 units. Finland is recommending 5,000 units for every adult. The FDA will hopefully adjust their RDA sometime soon!

Hi, Jay. I too have been LCHF consistently but only for 5 months. My question is - prior to beginning your ketogenic lifestyle, were you having any memory loss issues? I was having short term memory issues and still do but to a lesser degree. Just wondering if there is hope for me to restore my brain function to it's previous glory - not genius level but could assuredly rely on my brain for accurate recollection prior to about 10 years ago. Thanks so much for your time!